Issue of Terrorists' Rights to Test Obama's Pledge

The undertaking is an ambitious one. Fraught with legal complexities, it gives Republicans ample opportunity to score political points if he doesn't get it right. There's also the likelihood of a run-in with his former rival, Sen. John McCain, a former prisoner of war who before running for president staked his career on overhauling the nation's detainee policies.

"We look forward to working with the president and his administration on these issues, keeping in mind that the first priority of the U.S. government is to guarantee the security of the American people," McCain, R-Ariz., said in a joint statement with Sen. Lindsey Graham, R-S.C.

In his first week in office, Obama ordered Guantanamo Bay prison in Cuba to be closed within a year, CIA secret prisons shuttered and abusive interrogations ended.

So far, Obama's team has given every indication it will engage lawmakers, including Republicans, on the issue.

But once the two sides begin delving into details, there will be ample room for dispute.

Among the unknowns is how many of the 245 detainees now at Guantanamo Bay will be prosecuted.

Administration officials said that, pending an internal review, federal and military courts may be used. But, the officials added, a version of the secretive military tribunals, as established under President George W. Bush with the help of McCain, remains an option, too.

Obama could take a page from the Bush administration and try to revamp the system on his own, through executive order. But that approach failed for Bush, who angered members of his own party and wound up seeking congressional approval anyway after the Supreme Court in June 2006 ruled his tribunal system was unconstitutional.

Obama's other option is to seek legislation on the issue, potentially exposing his administration to a bruising fight with Republicans on how to handle the most dangerous of terrorism suspects.